Audio problem: Just before Dorothy has her operation, Mike is seated at her desk looking through her medical books. Sully pays a visit to comfort her. During their moment, you can hear slight foot shuffling from the camera crew in the foreground - which is not coming from the outside. Also, you hear a slight grunting during a pause in their conversation.
Visible crew/equipment: Loren wakes Dorothy in the middle of the night to mention selling the store and taking her on a trip to New York. While seated at her bedside, you can see shadows of a crew member on the bed pillows next to her, and hear some muffled foot movement while Loren is seated, talking to her.
A Washington Affair (1) - S3-E7
Continuity mistake: Jesse and Brian enter the President's office from The Secret passage shortly after Sen. Steward and Capt. Burgoyne leave. When the two boys hear the door rattle, Jesse whispers to Brian that somebody's coming and they race off Right. The President's desk is still in 3/4 view, and remains so as Burgoyne re-enters and goes to the desk, noticing the open cabinet door, which he checks. He hears movement and voices a threat, then goes to check the curtains only to find nothing. The camera then pans down to show Jesse and Brian hiding scared under the desk. Given the brief timespan, the two boys could not possibly have moved there without Burgyone noticing their presence.
The Library - S3-E5
Other mistake: Dr. Mike spots a charred Bible within the charred piles of books, and heads into the church. The Reverend is giving a sermon on morality, and offers Dr. Mike the floor and she briefs about certain stories in the book, which would be considered scandalous, without mentioning the book's title, then hands it to the Reverend who agrees such stories are scandalous, until he turns it over, to see that its 'The Holy Bible'. Being a Reverend, he should know The Bible cover to cover, but reacts surprised or shocked over the mentioning of the scandalous stories. (00:36:00 - 00:41:00)
Other mistake: In the scene where Dorothy decides to join the church picnic (just before her operation) Grace is talking to her and hands her a glass of cider as Robert E. approaches. The sky is partly cloudy, but the lighting changes slightly during the shot, and at one moment, appears too bright on Dorothy just before she sets the glass down and walks away.
Visible crew/equipment: When Sully visits Mike at the clinic, after dark, to console her over Dorothy's health condition. Watch as he moves past the window. You can see two control room blue screens in its reflection, alongside a boom mic, and the shadow of a long-haired crewman, who stands up, and then sits back down. Though the camera moves behind a potted plant on Mike's desk to conceal it all.
For Better or Worse (2) - S3-E29
Other mistake: Cloud Dancing gives Sully his white Cheyenne tribal dress to wear as a wedding suit, but Sully pulls on a very different deerskin coat inside the barbershop.
Answer: A Cooper was someone who made various things out of wood including wooden caskets and even barrels.